np990326p_si_001.pdf (16.61 kB)
DNA Polymerase β Inhibitors from Tetracera Boiviniana
journal contribution
posted on 1999-11-10, 00:00 authored by Ji Ma, Shelley R. Starck, Sidney M. HechtBioassay-guided fractionation of an active methyl ethyl ketone extract of Tetracera boiviniana, using a
sensitive assay to monitor DNA polymerase β inhibition, resulted in the isolation of three known
triterpenoids, betulinic acid (1), 3-cis-p-coumaroyl maslinic acid (2), and 3-trans-p-coumaroyl maslinic
acid (3). Compounds 1−3 inhibited DNA polymerase β with IC50 values of 14, 15, and 4.2 μM in the
presence of bovine serum albumin (BSA) and 6.5, 7.5, and 2.0 μM in the absence of BSA, respectively.
Further, compounds 1−3 potentiated the effects of bleomycin in cultured P-388D1 cells.